Sound barrier

ABSTRACT

A sound barrier for reducing noise is provided. The sound barrier may include at least one of a polyethylene, a thermoplastic, a thermoset, an elastomer, and a combination thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application No. 60/432,431 filed Dec. 11, 2002.

FIELD OF THE INVENTION

[0002] The invention relates to sound barriers, and more particularly,to sound barriers used in high traffic areas.

BACKGROUND OF THE INVENTION

[0003] Tire and engine noise emanating from cars, trucks and motorcyclesis a continuing problem for many neighborhood residents living alonghighways. Many residents of such neighborhoods are disheartened by thedecrease in resale value of their homes and properties due to noisepollution. People, especially children, living in high-traffic areas aresubject to stress and possibly serious long-term health implications.Children living in high-traffic areas have been shown to exhibit severalcommon signs of an at least modestly-elevated level of physiologicalstress, including elevated blood pressure, elevated heart-rate andhigher overnight cortisol levels.

[0004] In an attempt to solve the problems associated with high-trafficarea noise pollution, many State Departments of Transportation (DOTs)have constructed sound barriers. Sound barriers were originally devisedto reduce overall noise levels. Effective sound barriers typicallyreduce noise by as much as 50% or at least by 5-10 dB.

[0005] Sound barriers are not always required at locations where anabsolute noise threshold is met. There is no standard noise level thatrequires the construction of a sound barrier. Federal requirements forsound barriers may be found in Title 23 of the U.S. Code of FederalRegulations, Part 772, “Procedures for Abatement of Highway TrafficNoise and Construction Noise.”

[0006] A sound barrier can reduce the sound entering the community froma high-traffic area by either absorbing the sound, transmitting thesound, reflecting the sound back across the highway, or forcing thesound to take a longer path over and around the barrier. A sound barriermust be tall enough to block the view of a highway from the area that isto be protected, the receiver. To effectively reduce the noise comingaround the ends of a sound barrier, the sound barrier can be at leasteight times as long as the distance from the home or receiver to thesound barrier. To effectively reduce sound transmission through thesound barrier, the material used to construct the sound barrier must besufficiently dense and rigid.

[0007] Many of the existing sound barriers comprise concrete, masonry,wood, metal, and other sound-reflecting materials, which cause soundwaves to travel into nearby residential areas. These sound-reflectingbarriers are often constructed from concrete, sacrificing aestheticappeal, and do not meet acoustical performance standards. Additionally,these barriers require the use of massive machinery and specializedpersonnel for installation and transportation, are sensitive to stresscracking, and are susceptible to graffiti and vandalism. These soundbarriers are solid.

[0008] Other existing sound barriers are created from earth mounds orberms. Earth berms have a natural appearance and are usuallyaesthetically pleasing due to landscaping. Berms reduce noise byapproximately 3 dB more than a vertically-oriented concrete soundbarrier, but can require a lot of land and resources to construct.

[0009] A major consideration in the design of a sound barrier is itsvisual impact on the surrounding area. Addressing the size relationshipand providing staggered horizontal elements to a sound barrier canreduce the visual impact. Plants and landscaping are sometimes used inthe foreground to reduce the visual impact. The visual character ofsound barriers in relationship to their environmental setting needs alsoto be carefully considered.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a perspective view of a first embodiment of the soundbarrier of the present invention.

[0011]FIG. 2 is a perspective view of a second embodiment of the soundbarrier.

[0012]FIG. 3 is a perspective view of a third embodiment of the soundbarrier.

[0013]FIG. 4 is a perspective view of a fourth embodiment of the soundbarrier.

[0014] Before one embodiment of the invention is explained in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangements of the componentsset forth in the following description or illustrated in the drawings.The invention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is understood that thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including” and “comprising” and variations thereof herein is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In light of the limitations of existing sound barriers describedabove, new sound barriers are being sought. A need exists for a soundbarrier that is light-weight, easily installed and transported,economical, vandalism-resistant, easily maintained and replaced,environmentally-sound, shock-absorbing for increased safety in trafficaccidents, crack-resistant and aesthetically pleasing. Each embodimentof the present invention may achieve one or more of these results.

[0016] FIGS. 1-4 illustrate possible embodiments of the sound barrier ofthe present invention. In some embodiments of the present invention, thesound barrier comprises at least one of low-density polyethylene,linear-low polyethylene, high-density polyethylene, medium-densitypolyethylene, cross-linked polyethylene and combinations thereof.However, the sound barrier may comprise a variety of sound-absorbingmaterials, including without limitation, at least one of thermoplastics(such as polystyrene (PS), polyethylene-terepthalate (PET),polytetrafluoroethylene (PTFE), unplasticized polyvinyl chloride (PVC),plasticized polyvinyl chloride (pPVC), polypropylene (PP), polyamide(PA), and the like), thermosets (phenolics, melamine, unsaturatedpolyester, and the like), elastomers (silicone rubber, natural rubber,polybutadiene, and the like), and combinations thereof without departingfrom the spirit and scope of the present invention.

[0017] The polymer used to create the sound barrier can have a widevariety of order in molecular structure, and can therefore be comprisedof any of an amorphous, uncrosslinked thermoplastic, a semi-crystallinethermoplastic of intermediate order, a lightly-crosslinked elastomer,and a highly-crosslinked and cured thermosetting polymer. Sound barrierscomprising polymers can be recycled if damaged in use, thus, creating anenvironmentally-friendly sound barrier. Examples of crosslinking agentsthat may be used to produce the sound barrier may include withoutlimitation peroxide, Metton M1534 liquid molding resin, Metton M2150VOliquid molding resin, and Metton M2100VO liquid molding resin.

[0018] In some embodiments of the present invention, the sound barrieris fabricated using rotational molding processes. A variety ofrotational molding techniques are well-known and readily ascertainableby those of skill in the art. Some examples of rotational molds androtational molding techniques may be found in U.S. Pat. No. 6,383,437issued to Grieve on May 7, 2002, U.S. Pat. No. 6,296,792 issued to Payneon Oct. 2, 2001, U.S. Pat. No. 6,214,272 issued to Gruenwald et al. onApr. 10, 2001, and U.S. Pat. No. 6,030,557 issued to Payne on Feb. 29,2000, each of which is hereby fully incorporated by reference.Rotational molding is especially useful for economically creating large,seamless parts with uniform thickness and more material in the corners.Rotational molding does not require pre-stressing the material as otherplastics processing techniques do, thus increasing the strength anddurability of the finished product. Still, other fabrication techniquescapable of creating a durable product are possible and within the scopeof the present invention, including without limitation blow molding,thermoforming, injection molding, co-injection molding, and the like.

[0019] In some embodiments, the sound barrier further comprises UVstabilizers, such as benzophenones and DELRIN 527 UVN C010 mediumviscosity grade available from DuPont, which are added to the polymermelt to create a final product with improved resistance to UVdegradation and environmental stress cracking.

[0020] The sound barrier of the present invention can be used in anyhigh-traffic or other noisy area, including without limitation airports,residential traffic areas, highways, correctional facilities, industrialapplications, loading docks, utility power plants, waste treatmentfacilities, athletic facilities, pool areas, hospitals, firing ranges,and the like.

[0021] In some embodiments, the sound barrier may be hollow or have avoid defined therein, and can therefore be packed with a variety ofshock- and sound-absorbing materials, particularly, the sound-absorbingmaterials set forth above. The materials can be found in a variety ofshapes and sizes suitable for at least partially filling the void. Someof the embodiments of the present invention may be packed with recycledmaterial, such as ground-up tires and other recycled shock- andsound-absorbing materials. This embodiment creates a sound barrier thatis safer in the case of traffic accidents and is environmentally sound.Other embodiments of the present invention are packed with sand. Still,other packing materials, such as gravel, EPS foam and recycled carpet,are possible and within the scope of the present invention. Filling thevoid with these materials enhances the sound absorbing characteristicsof the sound barrier, especially when compared to solid sound barriers.

[0022] The sound barrier of the present invention may be easilymaintained, replaced and installed, can have a variety of productcolors, shapes and surface textures, and may be able to withstand avariety of weather conditions without rotting, rusting, warping,mildewing, molding, freezing, cracking or peeling. The sound barrier ofthe present invention can be made appropriate for any environment. Insome embodiments of the present invention, the sound barrier may beconstructed to look like stones or have a texture and color similar tothat of plants or bushes. The walls of the sound barrier may be easilycleaned, reducing the susceptibility to graffiti and vandalism.Additionally, the sound barrier of the present invention has improvedresistance to creep rupture and stress cracking and thus is ideal forearthquake-prone geographical regions.

[0023] In some of the embodiments, the sound barriers comprise stackablepanels, each panel comprising a plurality of ribs, as illustrated in thefigures. The ribs can be configured substantially horizontally (FIGS. 1and 2) or substantially vertically (FIGS. 3 and 4). The ribs can bepositive (see FIG. 1 for example) or negative (see FIG. 2 for example),allowing successive barrier panels to be joined together via a tongue ingroove or male-female relationship. In other embodiments, successivebarrier panels are joined by a plurality of pin-and-hole linkages,snap-fits, rods on a first panel slidably received in a groove on asecond panel, and any other joining configuration commonly known tothose of ordinary skill in the art.

[0024] In some embodiments, the barrier panels can be integrated intoexisting walls, using H-beams for structural support.

[0025] In some embodiments, the barrier has a height of approximatelythirteen feet. However, the sound barrier of the present invention canbe built in any dimension necessary for each particular application.

EXAMPLE

[0026] Installation Procedure:

[0027] 1. Install steel H-beams or pre-cast concrete structures. Beamsor posts should be set plumb and in-line with rigging and liftingdevices in a safe manner. The beams or posts shall be no more than a ½greater in width than the barrier panel width or greater in length thanthe barrier panel length.

[0028] 2. Lift a barrier panel from an A-frame on a loading truck intoposition adjacent the H-beams. Barrier panels should be lifted withproper and safe rigging and lifting devices.

[0029] 3. Fill the barrier panels with expandable foam, reused/recycledtires, or sand.

[0030] 4. Stack the barrier panels to a desired height ensuring that allbarrier panels sit level within any tolerances.

1. A sound barrier for reducing noise, the sound barrier comprising: anouter shell comprising at least one of a polyethylene, a thermoplastic,a thermoset, an elastomer, and a combination thereof; and a void definedtherein, the void being at least partially filled with at least one of asound-absorbing material, a shock-absorbing material and combinationthereof.
 2. The sound barrier of claim 1, wherein the outer shellcomprises a thermoplastic and the thermoplastic comprises at least oneof polystyrene (PS), polyethylene-terepthalate (PET), apolytetrafluoroethylene (PTFE), an unplasticized polyvinyl chloride(PVC), a plasticized polyvinyl chloride (pPVC), a polypropylene (PP), apolyamide (PA), and a combination thereof.
 3. The sound barrier of claim1, wherein the outer shell comprises a thermoset and the thermosetcomprises at least one of a phenolic, melamine, unsaturated polyester,and a combination thereof.
 4. The sound barrier of claim 1, wherein theouter shell comprises an elastomer and the elastomer comprises at leastone of silicone rubber, natural rubber, polybutadiene, and a combinationthereof.
 5. The sound barrier of claim 1, wherein the outer shellfurther comprises a UV stabilizer.
 6. The sound barrier of claim 1,wherein the void is at least partially filled with a sound-absorbingmaterial and the sound-absorbing material comprises at least one of apolyethylene, a thermoplastic, a thermoset, an elastomer, and acombination thereof.
 7. The sound barrier of claim 6, wherein the voidis at least partially filled with a sound-absorbing material and thesound-absorbing material comprises at least one of ground tire, gravel,sand, EPS foam, recycled carpet and combinations thereof.
 8. The soundbarrier of claim 1, wherein the outer shell comprises at least one oflow-density polyethylene, linear-low polyethylene, high-densitypolyethylene, medium-density polyethylene, cross-linked polyethylene andcombinations thereof.
 9. A method of manufacturing a sound barrier, themethod comprising: molding at least one of a polyethylene, athermoplastic, a thermoset, an elastomer, and a combination thereof toform a sound barrier having an outer shell and a void defined therein;and at least partially filling the void with a sound absorbing material.10. The method of claim 9, wherein the molding comprises at least one ofrotational molding, blow molding, thermoforming, injection molding,co-injection molding, and combinations thereof.
 11. The method of claim9, wherein the molding comprises rotational molding.
 12. The method ofclaim 9, wherein the sound barrier comprises a thermoplastic and thethermoplastic comprises at least one of polystyrene (PS),polyethylene-terepthalate (PET), a polytetrafluoroethylene (PTFE), anunplasticized polyvinyl chloride (PVC), a plasticized polyvinyl chloride(pPVC), a polypropylene (PP), a polyamide (PA), and a combinationthereof.
 13. The method of claim 9, wherein the sound barrier comprisesa thermoset and the thermoset comprises at least one of a phenolic,melamine, unsaturated polyester, and combination thereof.
 14. The methodof claim 9, wherein the sound barrier comprises an elastomer and theelastomer comprises at least one of silicone rubber, natural rubber,polybutadiene, and a combination thereof.
 15. The method of claim 9,wherein the sound barrier further comprises a UV stabilizer.
 16. Themethod of claim 9, wherein the void is at least partially filled with atleast one of a polyethylene, a thermoplastic, a thermoset, an elastomer,and a combination thereof.
 17. The method of claim 9, wherein the voidis at least partially filled with at least one of ground tire, gravel,sand, EPS foam, recycled carpet and combinations thereof.
 18. The methodof claim 9, wherein the outer shell comprises at least one oflow-density polyethylene, linear-low polyethylene, high-densitypolyethylene, medium-density polyethylene, cross-linked polyethylene andcombinations thereof.
 19. The method of claim 9, wherein the barrierreduces noise by at least about 5 dB in an area adjacent a noisy areawhen the sound barrier is placed therebetween.
 20. A sound barrier forreducing noise, the sound barrier comprising at least one of apolyethylene, thermoplastic, a thermoset, an elastomer, and acombination thereof, and reducing noise by at least about 5 dB in anarea adjacent a noisy area when the sound barrier is placedtherebetween.